This invention relates to measurement devices, and more particularly to a digital conversion adapter for magnetically coupled level meters.
Level sensing is used for a vast number of applications, perhaps the most familiar being for tanks containing liquids, such as fuel tanks. A limit level meter (also known as a switch level meter) provides readings at one or more predetermined levels. For example, a limit level meter may provide a reading only at a predetermined low level. A continuous level meter provides a continuous range of measurements from empty to full.
There are many different types of level meters, each type having a different principle of operation. Some of the more common types are float level meters, capacitive level meters, photoelectric level meters, and ultrasonic level meters.
Most level meters are designed to provide an analog readout at the meter. Therefore, a user must be physically present at a level meter in order to obtain and/or record a reading, at any given time.
In accordance with a particular embodiment of the present invention, a digital conversion adapter for a magnetically coupled level meter is provided. The adapter includes a first rotatable magnet located adjacent a second rotatable magnet of a level meter. The first rotatable magnet is operable to rotate in response to rotation of the second rotatable magnet. The second rotatable magnet may be operable to rotate in response to changes of a liquid surface level. An encoded disc is mechanically coupled with the first rotatable magnet and is operable to rotate in response to rotation of the first rotatable magnet. A light sensor array is operable to monitor a position of the encoded disc, with respect to the light sensor array, by reading a transmitter light, which passes through the encoded disc.
In accordance with another embodiment of the present invention, a light illuminator operable to direct source light through the encoded disc is provided. The light sensor array is operable to read a portion of the source light which passes through the encoded disc.
In accordance with yet another embodiment of the present invention, the light illuminator comprises a fiber guide. In this embodiment, the light sensor array may comprise a multiple fiber guide. A plurality of photodiodes operable to read the portion of the source light which passes through the encoded disc and the multiple fiber guide, may be provided at a remote location.
Technical advantages of particular embodiments of the present invention include a low cost adapter which is compatible with various types of float level meters. The adapter may be used in locations where electric or electronic devices are dangerous. The adapter may also be used in extreme temperatures.
Another technical advantage of particular embodiments of the present invention includes an adapter having high resolution and sensitivity, since there is nothing in physical contact with the rotating mechanism of the float level meter. Instead, only light comes in contact with the rotating mechanism. The adapter is suitable for use for automatic gas consumption charges to credit card systems.
Yet another technical advantage of particular embodiments of the present invention includes a digital conversion adapter which does not require calibration. The digital output is readily compatible with radio transmitters, and no analog-to-digital converter is required with the radio transmitter.